Amino Acid Peptide Research Articles

Efficient Neutralizing Antibodies Induction by Human Parvovirus B19 Epitope-Presenting Protein Nanoparticles.

Human parvovirus B19 (B19V) causes fetal hydrops in pregnant women. Despite the significant impact of this virus, effective vaccines remain unclear. In this study, we successfully engineered B19V protein nanoparticles by fusing the N-terminal receptor-binding domain corresponding to 5-80 amino acids of VP1 with two distinct types of self-assembling protein nanoparticles. Gel filtration and electron microscopic analysis confirmed the spherical assembly of the antigen-fused nanoparticles. The purified nanoparticles are efficiently bound to the surface of UT7/Epo-S1 cells, which are semi-permissive hosts for B19V infection. Immunization of BALB/c mice with VP1u 5-80 nanoparticles elicited a robust production of B19V-specific IgG antibodies compared to single VP1u 5-80 peptides. Moreover, a neutralization assay using B19V derived from a blood donor sample revealed that antibodies from mice immunized with VP1u 5-80 nanoparticles exhibited stronger infection-neutralizing activity. These findings suggest that nanoparticle formation plays a crucial role in enhancing the immunogenicity of the B19V VP1u 5-80 amino acid peptide and that these nanoparticles could serve as promising vaccine candidates, effectively inducing immunity against B19V.

Abstract 4136614: The design of novel therapeutics that target the L-type calcium channel to prevent hypertrophic cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is an inherited autosomal dominant disease of the sarcomere. Pathogenic features include ventricular hypertrophy, increased myofilament calcium sensitivity, myocardial fibrosis, and diastolic dysfunction. At the level of the myocyte there is cytoskeletal disarray, hypercontractility and altered mitochondrial function. Mitochondrial dysfunction is considered to be a key driver in HCM pathology. Research question: We previously demonstrated that the L-type Ca 2+ channel plays a role in the development of HCM facilitated by a structural-functional communication with mitochondria that can be regulated via the alpha interaction domain (AID) of the channel. In search of a preventative HCM therapy, we explored the efficacy of amino acid peptide variants that correspond to the AID of the cardiac L-type Ca 2+ channel. Methods and Results: Consistent with in silico predictions , competition binding assays confirmed that 4 variant peptides bound with higher affinity to the beta subunit than the AID peptide. In vitro studies confirmed that 3 of the 4 peptides could decrease the characteristic hypermetabolic state in myocytes isolated from a murine model of human HCM ( cTnI-G203S ). In vivo treatment of cTnI-G203S mice with peptide variants prevented the development of HCM and the development of fibrosis, in the absence of alterations in blood pressure, or kidney and liver function or changes in behaviour. Of note, the peptide variants also significantly improved contractile function. Similar effects were measured in αMHC 403/+ mice expressing the MYH6 mutation. Conclusions: Here we describe a first in class therapy that uniquely targets the L-type Ca 2+ channel to modify mitochondrial function and prevent hypertrophic cardiomyopathy. The peptides may be effective for treatment of HCM broadly because the mechanism of action involves the modification of mitochondrial function and impaired energy metabolism that is a common characteristic and driver of the pathology.

Liquid Crystal Behavior of Uniform Short Rods Made from Computationally Designed Parallel Coiled Coil Building Blocks.

Parallel, homotetrameric coiled coils were computationally designed using 29 amino acid peptides. These parallel coiled coils, called "bundlemers", have C2 symmetry, with all N-termini displayed from one end of the nanoparticle and all C-termini from the opposite end. This anisotropic display of the peptide termini allowed for the functionalization of two sets of nanoparticles with either maleimide or thiol functionality at the N-terminal region of the constituent peptides. The thiol-Michael conjugation reaction between the N-terminal end of complementary bundlemer nanoparticles formed monodisperse, rigid bundlemer dimer, called "dibundlemer", rods. The constituent, individual bundlemer nanoparticles were characterized with small-angle X-ray scattering (SAXS), Förster resonance energy transfer (FRET), and circular dichroism (CD) spectroscopy to confirm the parallel assembly of the coiled coils, consistent with the computational design. The dibundlemer rods were characterized with SAXS to reveal the uniform dibundlemer nature of the rods. Optical birefringence is observed in concentrated samples of the rods, with polarized optical microscopy (POM) revealing a nematic liquid crystalline behavior.

Peptide-Based Rapid and Selective Detection of Mercury in Aqueous Samples with Micro-Volume Glass Capillary Fluorometer

Mercury, a toxic heavy metal produced through both natural and anthropogenic processes, is found in all of Earth’s major systems. Mercury’s bioaccumulation characteristics in the human body have a significant impact on the liver, kidneys, brain, and muscles. In order to detect Hg2+ ions, a highly sensitive and specific fluorescent biosensor has been developed using a novel, modified seven amino acid peptide, FY7. The tyrosine ring in the FY7 peptide sequence forms a 2:1 complex with Hg2+ ions that are present in the water-based sample. As a result, the peptide’s fluorescence emission decreases with higher concentrations of Hg2+. The FY7 peptide’s performance was tested in the presence of Hg2+ ions and other metal ions, revealing its sensitivity and stability despite high concentrations. Conformational changes to the FY7 structure were confirmed by FTIR studies. Simultaneously, we designed a miniaturized setup to support an in-house-developed micro-volume capillary container for volume fluorometry measurements. We compared and verified the results from the micro-volume system with those from the commercial setup. The micro-volume capillary system accommodated only 2.9 µL of sample volume, allowing for rapid, sensitive, and selective detection of toxic mercury (II) ions as low as 0.02 µM.

Multi-Epitopic Peptide Vaccine Against Newcastle Disease Virus: Molecular Dynamics Simulation and Experimental Validation

Background: Newcastle disease virus (NDV) is a highly contagious and economically devastating pathogen affecting poultry worldwide, leading to significant losses in the poultry industry. Despite existing vaccines, outbreaks continue to occur, highlighting the need for more effective vaccination strategies. Developing a multi-epitopic peptide vaccine offers a promising approach to enhance protection against NDV. Objectives: Here, we aimed to design and evaluate a multi-epitopic vaccine against NDV using molecular dynamics (MD) simulation. Methodology: We retrieved NDV sequences for the fusion (F) protein and hemagglutinin–neuraminidase (HN) protein. Subsequently, B-cell and T-cell epitopes were predicted. The top potential epitopes were utilized to design the vaccine construct, which was subsequently docked against chicken TLR4 and MHC1 receptors to assess the immunological response. The resulting docked complex underwent a 1 microsecond (1000 ns) MD simulation. For experimental evaluation, the vaccine’s efficacy was assessed in mice and chickens using a controlled study design, where animals were randomly divided into groups receiving either a local ND vaccine or the peptide vaccine or a control treatment. Results: The 40 amino acid peptide vaccine demonstrated strong binding affinity and stability within the TLR4 and MHC1 receptor–peptide complexes. The root mean square deviation of peptide vaccine and TLR4 receptor showed rapid stabilization after an initial repositioning. The root mean square fluctuation revealed relatively low fluctuations (below 3 Å) for the TLR4 receptor, while the peptide exhibited higher fluctuations. The overall binding energy of the peptide vaccine with TLR4 and MHC1 receptors amounted to −15.7 kcal·mol−1 and −36.8 kcal·mol−1, respectively. For experimental evaluations in mice and chicken, the peptide vaccine was synthesized using services of GeneScript Biotech® (Singapore) PTE Limited. Experimental evaluations showed a significant immune response in both mice and chickens, with the vaccine eliciting robust antibody production, as evidenced by increasing HI titers over time. Statistical analysis was performed using an independent t-test with Type-II error to compare the groups, calculating the p-values to determine the significance of the immune response between different groups. Conclusions: Multi-epitopic peptide vaccine has demonstrated a good immunological response in natural hosts.

Construction of Aryl Azide‐ and Triazole‐Based Unnatural Amino Acid Motifs via the Pd(II)‐Catalyzed C(sp3)−H Arylation

AbstractThis paper reports a method for the synthesis of examples of aryl azide‐ and triazole moiety‐based unnatural amino acid motifs using the Pd(II)‐catalyzed arylation of the prochiral C(sp3)−H bonds of carboxamides of amino acids as one of the key transformations. Synthesis of racemic and enantioenriched aryl azide‐based unnatural amino acid motifs including, norvaline, leucine, norleucine, phenylalanine, 2‐aminobutyric acid, 2‐aminooctanoic acid, and non‐α‐amino acid derivatives were shown. Additionally, we attempted the synthesis of triazole moiety‐installed norvaline, leucine, norleucine, phenylalanine, 2‐aminobutyric acid, 2‐aminooctanoic acid, and non‐α‐amino acid derivatives via the Cu‐catalyzed Click reaction. We also demonstrated the removal of the protecting groups and the synthesis of free amino group‐containing aryl azide‐ or triazole‐based unnatural amino acid motifs and peptides. Generally, azide moiety‐containing unnatural amino acid motifs are important molecular tools in chemical biology. Furthermore, aryl azide‐ and triazole moiety‐containing unnatural amino acid scaffolds are notable substrates in medicinal chemistry and drug discovery research. Accordingly, this work contributes to enriching the library of aryl azide‐ and triazole‐based unnatural amino acid derivatives.

Surface immobilization and properties optimization of phage hydrolase against Gram-negative bacteria

Immobilized hydrolase not only reduces the production of antibiotic-resistant bacteria, but also effectively improves the stability of hydrolase in external use. In this study, phage hydrolase LysSSE1 against Gram-negative bacteria were surface immobilized and optimized for their bactericidal activity. Different anti-pathogen surface materials were prepared, where LysSSE1 was immobilized on the glass surface with a silica-affinity peptide and into which different peptide linkers were introduced. Immobilized enzymes inserted into the natural amino acid peptide linker exhibited higher bactericidal activity, greater stability, and more consistent bactericidal performance compared to those without the peptide linker. Among these immobilized enzymes, LysSSE1-NL-SiAP1 exhibited the strongest bactericidal activity and the best repeatable bactericidal performance, which only reduced the original performance by about 5% after three bactericidal cycles. Modeling analysis suggested that the presence of peptide linker might increase the molecular flexibility of the proximal hydrolase domain to better interact with the bacterial substrate. Our surface immobilization strategy could be extended to other lytic proteins, providing support for the development of surface sterilization methods and materials.

Hypothyroidism Induced by a TSH Receptor Peptide-Implications for Thyroid Autoimmunity.

Background: The "neutral" thyrotropin receptor autoantibodies (N-TSHR-Ab) directed at the TSHR ectodomain's hinge region have been shown to induce thyroid cell damage in vitro. During these earlier studies, we developed a mouse monoclonal antibody (MC1) specific for a peptide (amino acid 322-340) in the region (MC1-Mab) which was able to induce thyroid cell stress and apoptosis when administered invivo. Methods: In order to examine the effect of invivo generated N-TSHR-Abs, rather than an acutely administered monoclonal antibody, we immunized Balb/c mice with the hinge region peptide over 18 weeks. Serum TSHR antibodies, specific TSHR hinge region antibodies, serum thyroglobulin (TG) and anti-TG as well as thyroxine and thyrotropin (TSH) levels were examined to evaluate the response to the immunization. Histological examination of the thyroid glands and flow cytometry of spleen T cells, B cells and macrophages were also performed to explore the underlying mechanisms. Results: We found that TSHR-peptide immunized mice developed N-TSHR-Abs against the peptide which resulted in thyroid damage shown by thyroid follicular destruction with follicular cell apoptosis, M1 macrophage infiltration, thyroglobulin release, and induction of thyroglobulin antibodies. This resulted in hypothyroidism with increased TSH levels. Conclusion: This study demonstrated that endogenous neutral antibodies to the TSHR could induce thyroid cell damage from apoptosis and M1 macrophage infiltration and resulted in hypothyroidism.

Enhancing Antimicrobial Peptide Activity through Modifications of Charge, Hydrophobicity, and Structure.

Antimicrobial peptides (AMPs) are emerging as a promising alternative to traditional antibiotics due to their ability to disturb bacterial membranes and/or their intracellular processes, offering a potential solution to the growing problem of antimicrobial resistance. AMP effectiveness is governed by factors such as net charge, hydrophobicity, and the ability to form amphipathic secondary structures. When properly balanced, these characteristics enable AMPs to selectively target bacterial membranes while sparing eukaryotic cells. This review focuses on the roles of positive charge, hydrophobicity, and structure in influencing AMP activity and toxicity, and explores strategies to optimize them for enhanced therapeutic potential. We highlight the delicate balance between these properties and how various modifications, including amino acid substitutions, peptide tagging, or lipid conjugation, can either enhance or impair AMP performance. Notably, an increase in these parameters does not always yield the best results; sometimes, a slight reduction in charge, hydrophobicity, or structural stability improves the overall AMP therapeutic potential. Understanding these complex interactions is key to developing AMPs with greater antimicrobial activity and reduced toxicity, making them viable candidates in the fight against antibiotic-resistant bacteria.

Fast and Selective Cysteine Conjugation Using para-Quinone Methides.

An efficient and selective method for cysteine conjugation utilizing para-quinone methides (p-QMs) was developed. p-QM labeling exhibits high specificity toward the cysteine residue, as evidenced by its reactivity with various amino acid derivatives, peptides, and proteins. Notably, the p-QM-cysteine reactions display robust kinetics with rate constants up to 1.67 × 104 M-1·s-1. Furthermore, p-QM conjugation enables us to attach a fluorescent probe to a HER2 nanobody, resulting in selective labeling of HER2-positive SK-BR-3 cells.

7492 Fibroblast Growth Factor 21 In The Diagnosis And Treatment Of Metabolic Disorders

Abstract Disclosure: H.M. Heshmati: None. H.S. Abu-Lebdeh: None. Background: Fibroblast growth factor 21 (FGF21), a member of the human FGF superfamily, is a 181 amino acid peptide hormone primarily produced by the liver. The gene of FGF21, located on chromosome 19, was cloned in 2000. FGF21 is involved in the maintenance of metabolic homeostasis. This review presents an update on the relevance of FGF21 in the diagnosis and treatment of metabolic disorders including obesity, nonalcoholic fatty liver disease (NAFLD), dyslipidemia, and type 2 diabetes. Methods: A systematic search of literature was conducted using the search terms fibroblast growth factor 21, obesity, nonalcoholic fatty liver disease, dyslipidemia, and type 2 diabetes. Results: FGF21 is a stress hormone with effects on energy expenditure and metabolism of lipids and glucose. FGF21 exerts its endocrine action in the central nervous system and adipose tissue. The serum FGF21 levels in normal subjects increase with aging. Stressful conditions (e.g., fasting status, protein restriction, exercise, metabolic disorders, kidney diseases, cardiovascular diseases, and sepsis) increase FGF21 secretion. Serum FGF21 levels are increased in obesity, NAFLD, dyslipidemia, and type 2 diabetes. Some of these patients may have a state of FGF21 resistance. The resistance to FGF21 is related, at least in part, to the presence of high circulating levels of fibroblast activation protein, a protease that inactivates FGF21. It has been suggested that the exercise-induced weight loss can be due to increased FGF21 secretion and decreased FGF21 resistance in adipose tissue. Serum FGF21 level has the potential to be used as a biomarker for early diagnosis of metabolic disorders (e.g., NAFLD and type 2 diabetes). Based on different metabolic properties of FGF21, FGF21-based therapy has been considered as an attractive approach for the treatment of metabolic disorders. Since native FGF21 has poor pharmacodynamic properties (e.g., short half-life and proteolytic cleavage by proteases), long-acting FGF21 analogs (e.g., LY2405319, PF-05231023, pegozafermin, AKR-001, and LLF580) have been synthesized and tested in clinical trials for the treatment of obesity, NAFLD, dyslipidemia, and type 2 diabetes. The available results show that FGF21 analogs can reduce body weight, liver fat, blood lipids, and fasting insulin/insulin resistance. Overall, the treatment with these analogs is safe and well tolerated. Conclusion: FGF21 is a predominantly liver-derived peptide hormone regulating energy expenditure and metabolism of lipids and glucose. Serum FGF21 levels are increased in several metabolic disorders including obesity, NAFLD, dyslipidemia, and type 2 diabetes. FGF21 is an attractive target for the treatment of these metabolic disorders. Despite some promising results observed with the use of FGF21 analogs, more clinical studies are needed before recommending FGF21-based therapies in metabolic disorders. Presentation: 6/2/2024

A-038 Interlaboratory Comparison of Parathyroid Hormone Analytical Results Across Clinical Assays from 8 Manufacturers - Steps Towards Standardization

Abstract Background Parathyroid hormone (PTH) is an 84 amino acid peptide produced by the parathyroid gland and is a key biomarker used for the diagnosis and treatment of Chronic Kidney Disease-Mineral and Bone Disorder, as well as hypo- and hyperparathyroidism. PTH clinical assays were previously reported to exhibit significant inter-assay measurement variability, which limits the utility of PTH as a diagnostic biomarker and can result in the misclassification of patients. Thus, there is a need for PTH clinical assay standardization to improve clinical assay measurement agreement. The Centers for Disease Control and Prevention’s Clinical Standardization Program (CDC-CSP) will launch a PTH standardization program, which is in support of and coordinated with the IFCC Committee on Bone Metabolism. In preparation, the CDC-CSP conducted an Inter-Laboratory Comparison Study to evaluate the current status of PTH inter-assay variability and to investigate potential sources of variability. Methods Eight PTH assay manufacturer’s laboratories measured PTH in 42 deidentified, fresh-frozen single donor serum samples in duplicate over 2 independent runs. Sample PTH concentrations ranged from 1.3 - 324 pg/mL, based on initial screening values. Five manufacturers submitted data for 2 different assays, resulting in PTH measurements from 13 assays total. Data were submitted to the CDC CSP for analysis. Results Assay precision was <5% for 10/13 measurement procedures (MP) assessed and 3 MPs exhibited precisions between 5 - 18%. Assay-specific PTH measurements demonstrated good linear correlation compared to the all-assay mean concentration. Interestingly, inter-assay variability increased with increasing PTH concentrations, with individual sample standard deviations increasing from 2.9 - 123, with a mean SD of 24.1 and individual sample CVs increasing from 18.9 - 44.5%, with a mean CV of 24.2%. Conclusions This study provides new insights into PTH inter-assay variability and assay performance for assays commonly used in the clinical setting. The findings of this PTH Interlaboratory Comparison Study establish a baseline for PTH inter-assay variability and will guide future PTH standardization efforts.

The Epiphyte Bacillus sp. G2112 Produces a Large Diversity of Nobilamide Peptides That Promote Biofilm Formation in Pseudomonads and Mycobacterium aurum.

Bacillus sp. G2112, an isolate from cucumber plants that inhibited plant pathogens, produces not only surfactins, iturins, and fengycins common to many Bacillus spp., but also a large variety of N-acyl-(depsi)peptides related to A-3302-B and nobilamides. Four known and fourteen previously unreported nobilamide peptides were characterized using high-resolution mass spectrometry, tandem mass spectrometry, and NMR. The stereochemistry of the amino acids of nobilamide peptides was determined using Marfey's method. The diversity of nobilamide peptides from Bacillus sp. G2112 resulted from the incorporation of different acyl groups and amino acids in the sequence. The peptides occur in linear or cyclic form. In addition, a truncated N-acetylpentapeptide was produced. Agar diffusion assays with selected nobilamide peptides against plant pathogens and human pathogens revealed that A-3302-B and its N-acyl homologs, A-3302-A and nobilamide J, exhibited powerful antibiotic activity (at 5 µg/hole) against Lysinibacillus sphaericus that can cause severe sepsis and bacteremia in patients. Moreover, nobilamide peptides from Bacillus sp. G2112 strongly promoted biofilm formation in the Gram-positive Mycobacterium aurum and Gram-negative pseudomonads. Structurally diverse nobilamides from Bacillus sp. G2112, whether linear or cyclic, penta and heptapeptides, induced biofilm formation, suggesting that the common N-acetyl-D-Phe-D-Leu-L-Phe-D-allo-Thr-L-Val amino acid sequence motif is important for the biofilm-inducing activity.

Novel H-2Db-restricted CD8 epitope derived from mouse MAGE-type antigen P1A mediates antitumor immunity in C57BL/6 mice

BackgroundMelanoma antigen gene (MAGE)-type antigens are promising targets for cancer immunotherapy as they are expressed in cancer cells but not in normal tissues, except for male germline cells. The mouse...

Hemp Seed Protein Hydrolysate Enriched with γ-Aminobutyric Acid and Peptides by Microbial Bioconversion

Hemp seed protein (HSP), a by-product of hemp oil processing, was converted into a functional protein ingredient enriched with γ-aminobutyric acid (GABA) and peptides through a two-step microbial fermentation process. To enhance peptide and free amino acid production from HSP, it was hydrolyzed using alkaline protease produced by Bacillus subtilis HA. The HSP was hydrolyzed at a degree of 40% at 55 °C for 24 h, yielding a pH of 6.55, an acidity of 1.22%, and 205.45 mg% tyrosine equivalents. This process resulted in the production of low molecular-weight peptides. (<5000 Da) The total amino acid content and branched-chain amino acids (leucine, isoleucine, and valine) were 6.78 mg/g and 1.47 mg/g. Subsequently, the production of γ-aminobutyric acid (GABA) in the HSP hydrolysate was optimized through co-fermentation with lactic acid bacteria in the presence of 5% MSG at 30 °C for 5 days. The serial co-fermented HSP hydrolysate exhibited a GABA content of 33.98 mg/g and a viable bacterial count of 9.51 log CFU/mL for Lb. plantarum KS2020. This serial co-fermentation process, combining proteolysis and lactic acid fermentation, not only increased the peptide content but also promoted GABA accumulation, positioning HSP hydrolysate as a promising candidate for functional foods with potential health benefits.

Preparation and anticancer activity of telomerase inhibitor TAT-LPTS39 polypeptide.

Telomerase is activated in most cancer cells, and thus telomerase is an ideal target for cancer therapy. The human liver-associated candidate tumour suppressor LPTS/PinX1, is the only human protein reported to bind with the telomerase catalytic subunit telomerase reverse transcriptase (TERT) and inhibit telomerase activity. The C-terminal fragment of LPTS/PinX1 (LPTS/PinX1290-328) contains a telomerase inhibitory domain that is needed for inhibition of telomere elongation and induction of apoptosis. This study prepared the TAT-LPTS39 (TAT-LPTS/PinX1290-328) polypeptide and analysed its effect of the tumour growth. LPTS/PinX1290-328 was fused with TAT [11 amino acid (aa) peptide of the HIV transactivator of transcription protein] to generate the recombinant protein GST-TAT-LPTS39 and was transduced into cells. Telomerase activity was identified by the telomeric repeat amplification protocol (TRAP) and the relative telomere length (RTL) was measured by quantitative real-time polymerase chain reaction (qPCR). The effects of the TAT-LPTS39 protein on cell growth and death were evaluated by 3-(4,5-dimethylthiazolyl)-2,5-diphenyltetrazolium bromide (MTT), cell culture doubling time and flow cytometry assays. The cell derived xenograft (CDX) model was used to examine tumour growth inhibition effect of TAT-LPTS39 polypeptide in vivo. We successfully expressed and purified the recombinant protein GST-TAT-LPTS39 in vitro. The GST-TAT-LPTS39 protein was efficiently delivered into cells, inhibited telomerase activity and the growth of the telomerase-positive liver cancer cells BEL-7404 and QGY7701, and induced the senescence and apoptosis in telomerase-positive Hela, BEL-7404 and QGY7701 cells, but was ineffective to telomerase-negative cells in vitro. The TAT-LPTS39 polypeptide without the GST tag similarly inhibited the growth of telomerase-positive cancer cells Hela and PLC-PRF-5 in vitro, BEL-7404 CDX tumour in vivo and shortened telomere length. The TAT-LPTS39 polypeptide has the ability to inhibit telomerase activity and suppress the growth of all tested human telomerase-positive cancer cells in vitro and in vivo, suggesting a potential anticancer drug development.

A Novel Antigen Design Strategy to Isolate Single-Domain Antibodies that Target Human Nav1.7 and Reduce Pain in Animal Models.

Genetic studies have identified the voltage-gated sodium channel 1.7 (Nav1.7) as pain target. Due to the ineffectiveness of small molecules and monoclonal antibodies as therapeutics for pain, single-domain antibodies (VHHs) are developed against the human Nav1.7 (hNav1.7) using a novel antigen presentation strategy. A 70 amino-acid peptide from the hNav1.7 protein is identified as a target antigen. A recombinant version of this peptide is grafted into the complementarity determining region 3 (CDR3) loop of an inert VHH in order to maintain the native 3D conformation of the peptide. This antigen is used to isolate one VHH able to i) bind hNav1.7, ii) slow the deactivation of hNav1.7, iii) reduce the ability of eliciting action potentials in nociceptors, and iv) reverse hyperalgesia in in vivo rat and mouse models. This VHH exhibits the potential to be developed as a therapeutic capable of suppressing pain. This novel antigen presentation strategy can be applied to develop biologics against other difficult targets such as ion channels, transporters and GPCRs.

A novel antifungal peptide, SP1.2, from Rhodopseudomonas palustris against the rice blast pathogen.

Rice blast has a significant detrimental impact on rice yields, so developing efficient biological control technologies is an effective means for rice blast prevention and control. The GroEL protein has proven to be effective at preventing and managing the pathogenicity of rice blast. Here, we analyzed the amino acid sequence of the GroEL protein and synthesized the '60 kDa chaperonin signature' (350-373 amino acids) peptide SP1.2, which has potent antifungal activity. Notably, the SP1.2 peptide exhibited potent fungicidal activity against Magnaporthe oryzae, effectively inhibiting appressorium germination. Electron microscopy revealed that SP1.2 disrupted the fungal plasma membrane and bound to multiple bioactive phosphoinositides in vitro, triggering the production of reactive oxygen species. Furthermore, it also caused an increase in the acetylation of M. oryzae and induced autophagy in cells. The spray application of SP1.2 significantly reduced the number of disease spots caused by the fungal pathogen M. oryzae in rice, enhancing the defense response of rice plants. Field trials showed that the control effect was 64.59% after spraying SP1.2. Our study illustrates the antifungal activity of the structurally unique SP1.2 peptide against plant fungal pathogens and paves the way for the future development of this class of peptides as antifungal agents. © 2024 Society of Chemical Industry.

Differences in the Renal Accumulation of Radiogallium-Labeled (Glu)14 Peptides Containing Different Optical Isomers of Glutamic Acid.

Acidic amino acid peptides have a high affinity for bone. Previously, we demonstrated that radiogallium complex-conjugated oligo-acidic amino acids possess promising properties as bone-seeking radiopharmaceuticals. Here, to elucidate the effect of stereoisomers of Glu in Glu-containing peptides [(Glu)14] on their accumulation in the kidney, the biodistributions of [67Ga]Ga-N,N'-bis-[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N'-diacetic acid-conjugated (l-Glu)14 ([67Ga]Ga-HBED-CC-(l-Glu)14), [67Ga]Ga-HBED-CC-(d-Glu)14, [67Ga]Ga-HBED-CC-(dl-Glu)14, and [67Ga]Ga-HBED-CC-(d-Glu-l-Glu)7 were compared. Although the accumulation of these compounds in the bone was comparable, their kidney accumulation and retention were strikingly different, with [67Ga]Ga-HBED-CC-(d-Glu-l-Glu)7 exhibiting the lowest level of kidney accumulation among these compounds. Repeated d- and l-peptides may be a useful method for reducing renal accumulation in some cases.

Nicotinamide benefited amino acid metabolism and rumen fermentation pattern to improve growth performance of growing lambs.

Nicotinamide (NAM) is easily degraded in the rumen, the rumen-protected NAM (RPN) supplementation might enable the use of NAM in ruminants. This study aimed to elucidate the effects of RPN supplementation on growth performance, rumen fermentation, antioxidant status and AA metabolism in growing lambs. A total of 128 healthy and similar lambs (21.3 ± 0.28 kg, 70 ± 6.3 days of age) were allotted to 1 of 4 groups. The treatments were 0, 0.5, 1 and 2 g/d RPN supplementation. The RPN products (50% bioavailability) were fed at 0700 h every day for 12 weeks. All lambs were fed the same pelleted total mixed rations to allow ad libitum consumption and had free access to water. The RPN tended to increase the average daily gain and feed efficiency. The tendencies of RPN × Day interaction were found for dry matter intake during the entire study (P = 0.078 and 0.073, respectively). The proportions of acetic acid, isobutyric acid and isovaleric acid were decreased, whereas the proportions of propionic acid and valeric acid were increased (P < 0.05). The ratio of acetic acid to propionic acid was decreased (P < 0.05). Moreover, the antioxidative status was enhanced and the glucose concentration was increased by RPN (P < 0.05). In addition, 17 amino acids (AAs) were detected in plasma, of which 11 AAs were increased by RPN (P < 0.05). Plasma metabolomics analysis identified 1395 compounds belonging to 15 classes, among which 7 peptides were significantly changed after RPN supplementation. Overall, the results suggested that RPN supplementation favoured the rumen fermentation pattern to propionic acid-type with benefited glucose metabolism, enhanced antioxidant capacity, and changed the AA and small peptide metabolism. This study provides a new perspective for studying the relationship between vitamin and AA metabolism.